Three-dimensional structure-activity relationships of synthetic pyrethroids: 1. Similarity in bioactive conformations and their structure-activity pattern

The three-dimensional "bioactive" conformations of various types of pyrethr oid insecticides were deduced from among optimized conformations which were generated on the basis of the exhaustive conformational exploration of the reference compound, MTI-800. A "folded" rather than an "extended" conforma tion was proposed to be the "bioactive structure" of pyrethroid molecules i ncluded in this study. The folded "bioactive" structures were further analy zed in terms of molecular (dis)similarity indices to elucidate the effect o f the "local" structural variations on the activity. The results indicate t hat the overall bioactive conformation as well as the local 3D similarity o f the molecule are important in governing the potency variations in the ins ecticidal activity.